I had a similar situation when I replaced my old graphics card; my old monitor didn't have the right kind of connector, so I had to buy a new monitor as well. I could have gotten an adapter, but the old monitor was slightly wonky so I decided it was as good a time as any to replace it.
Noticed a subtle little easter egg early on: a brief close-up on the ice cream Hajime was eating shows it is "Tatsunoko" brand. (The cup says "Tatsunoko Hyper Cup".) This series is made by the studio Tatsunoko Production.
Considering the context and his laugh afterwards, I think it was some...
The Angel designs do get very imaginative; it really helps sell that these are not just your stock-standard alien invaders.
By the way, I don't think you ever said whether you'd like to see the names of the angels and what their traditional occult associations are.
I agree that it's probably the conclusion the viewer is intended to side with, but it keeps it ambiguous enough not to make the other side obviously wrong, at least early on.
Edit: and yes, the bot character is interesting, and her existence in the new world raises even more questions.
I don't think the colours correspond to anything specific (other than grey possibly being "You can't grasp the true form of my mind".) Rather the same colour just indicates being on the same general "wavelength".